Attached a diagram one of our members made.
Also in our files section there is a water heater troubleshooting file
https://www.montanaowners.com/forums...hp?do=cat&id=3
If you drained the water heater I'm guessing you put it in bypass mode. ( water heater bypass on/off, ON). Make sure Winterize is OFF. And Normal flow is selected on the fill valve.
Don't forget to turn on your tank heaters but only if they have liquid in them. Also use your furnace to keep your underbelly warm.